The invention relates to a clamping device with a connection for cable strands, the clamping device being formed from a clamping tube and a mandrel-like contact part that can be held in the clamping tube by screwing, a funnel-shaped opening being provided on the clamping tube, into which opening the bared cable strands can be inserted as far as an inner connection chamber, and the contact part being able to be screwed with its tip and its conical surface into the cable strands and the strands being pressed against a clamping shoulder in the end of the connection.
A clamping device of this kind is provided to connect high-current connections with cable strands mechanically fixedly to the contact element, wherein even high tensile forces and vibrations cannot cause any undesirable separation of the connection.
It is known to connect the connection end of cable strands with crimp connections to a contact element, or to connect cable strands to contact elements in which a cone-shaped contact part in a contact element presses the stranded conductors by means of axial or radial forces onto a correspondingly formed opposing surface, the angles of the conical surfaces being the same, however.
A clamping device of this kind for connecting cable strands is described in DE 89 14 460 U1.
It is disadvantageous in this case that such clamping devices have a relatively large structural volume or do not possess sufficiently great long-term stability with regard to security against pulling out or vibration. The object of the invention is therefore to create a detachable connection between a contact element of the type named at the beginning and a cable strand to the effect that, in addition to optimal electrical contact properties, the cable strand is held in the contact element with a high degree of security against pulling out, especially in the event of vibration influences.
This object is achieved in that the contact part has a cone-shaped tip, the conical surface of which is at an angle xcex1 to the vertical, that on its side facing the conical surface of the contact part the clamping shoulder has a conical surface at an angle xcex2 to the vertical, and that the angle xcex1 of the conical surface of the tip of the contact part is smaller than the angle xcex2 of the conical surface of the clamping shoulder, and that the contact part can only be screwed so far into the connection chamber, and into the cable strand inserted therein, that a minimum overlap remains between the conical surface of the contact part and the conical surface of the shoulder.
In a nreferred embodiment of the invention the angle (xcex1) of the conical surface of the contact part and the angle (xcex2) of the conical surface on the clamping shoulder is at least 2.5xc2x0.
The advantages achieved with the invention consist in particular in the fact that, in the case of a high-current contact that is developed as a terminal connection with a clamping device for connection for cable strands with a clamping tube and a centrally guided contact part, which is pressed axially into the centre of the cable strands inserted into a connection chamber, and due to different angles of a conical surface of a clamping shoulder and the conically shaped tip of the contact part, a substantially greater squeezing is achieved in the conical zone than is possible with conventional designs in which the angles of the conical surfaces are executed parallel.
This results in turn in greater long-term stability with reference to the electrical contacting, improved resistance to loosening of the clamping in the event of vibrations and finally, due to the gas-tight squeezing achieved hereby, also to optimal electrical contact resistances.
Furthermore, the security of the cable strands against being pulled out of the contact element is far higher compared with contact elements of this kind that are already known.
A further advantage of this embodiment is that the cable strands no longer xe2x80x9crollxe2x80x9d too when being screwed tight and thus no longer cause any grating noises.
A practical example of the invention is shown in the drawing and is explained in greater detail below.